Cleaning and Restoring an Antique Finish

So you have an old piece of furniture, and the finish isn't all that great on it. Your first thought might be;"Hey. I should get rid of this old finish and put something new on instead." Please don't.
That old piece of furniture has, quite likely, lived longer than you have. The finish may be failing, but the wood and finish have lived together for a long time, developing what antique lovers call "patina". Patina is what happens when dust, wax, light, and wear act together to change and enrich a piece of wood. It can't be faked (well, it can, but it's really difficult), it just takes decades and centuries to develop. So what can we do that will clean a piece of furniture without destroying the finish? Well, we can refresh it.

We start by mixing equal parts of turpentine and the two linseed oils together in the mason jar. This is your cleaning solution. We will apply it with the quad-nought steel wool. And then wipe it off with a lint free rag. Pretty simple.
I had to clean a vanity, so that's what I'm using for this Instructable. The mirror has already been removed in order to transport it, so we don't have to worry about that. The finish is actually damaged on top, but that's not what we're going to be worrying about. We will just clean the piece.

First, flood the area with cleaner. Really, that just means use enough to get a thin layer over everything. With the steel wool, lightly polish the old finish. You can rub a bit harder on areas that have top-of-finish dirt; paint, nail polish, actual dirt. But the idea is to only clean the very top of the old finish. You don't want to damage or, heaven forfend, rub through the old finish.

With an antique, or simply old piece of furniture, the finish you are cleaning is likely shellac or varnish--with varnish the more likely of the two. Varnish is traditionally a combination of a drying oil, a resin, and a thinner or solvent. The older the furniture, the more likely that the drying oil is from a naturally occurring oil--usually linseed. This means that the cleaner you are applying will ultimately bond with the old varnish and then polymerize.

So once you have given the furniture a light scrub, wipe the cleaner off with a lint-free rag. Don't try and wipe it dry, just give it a moderate wipe. This will leave a fine layer of cleaner behind that will very quickly polymerize into a new film.

Polymerization of linseed oil is a pretty straightforward process; molecules of the linseed oil link up with atmospheric oxygen to form long chain molecules, thus forming a film on your furniture. The nice part of this is that the linseed oil, once polymerized, is very accepting of new topcoats over it. For antiques or older furniture I would use a natural oil varnish (like Tried and True Varnish Oil), because it's more period-appropriate than a urethane varnish. Top it all with a nicely buffed coat of wax and your furniture will look lovely without losing its developed colour.